Polarized relay



R. J. JOSEPH POLARIZED RELAY Sept. 2, 1952 ZSHEE'I'S -SHEETI Filed Nov. 29, 1949 Inventor RAYMOND JJOSEPH B7 3'? Attorneys R. J. JOSEPH POLARIZED RELAY Sept. 2, 1952 Filed Nov. 29, 1949 2SHEETS-SHBET2 Patented Sept. 2, 1952 POLARIZED RELAY Raymond John Joseph, Ferndown, Northwood Hills, England, assignor to E. Shipton & Company Limited, Ferndown', Northwood Hills, England, a British company Application November 29, 1949, Serial No. 130,047 In Great Britain November 29, 1948 11 Claims. 1

The present nvention relates to polarised relays and more particularly to high speed polarised relays such as of the kind known as Carpenter relays, and has for its object to provide an improved contact assembly whereby bouncing of the contacts is reduced to a minimum.

According to the present invention, the moving contacts carried by th balanced armature are supported by a spring arrangement comprising a central leaf spring which carries an insulated member at its free end by which the contacts are supported, and wherein two further leaf springs are disposed one on each side of the first leaf spring, each being secured at one end to the armature and having their free ends pressing on opposite sides of the insulating member carrying the contacts. For most eifective reduction of contact bouncing, the free ends of this pair of outer leaf springs should press on the insulating material as closely as possible to the contacts, and according to a feature of the invention the portions of the surface of the insulating material between the contacts and the free ends of the leaf springs is provided with a ridge, groove or the like for increasing the surface length of the insulating material between the contacts and the springs in order to reduce electrical leakage between these members.

In order that the invention maybe more clearly understood reference will now be made to the accompanying drawings, in which:

Fig. 1 shows a front View, partly in section, of a relay according to the invention;

2 shows a side view of Fig. 1;

Fig. 3 shows a back view of Fig. 1;

Fig. 4 shows a section along the line 4-4 in Fig, 1; i i i Fig. 5 shows an enlarged perspective view of the armature assembly;

Fig. 6 shows a front view of a modified construction;

Fig. 7 shows a side view of Fig. 6.

Referring to the embodiment shown in Figs. 1 to 5 the relay comprises a non-magnetic frame I, preferably made as a die-casting, having a cavity in the back thereof into which fits a permanent magnet 2. At its lower end the permanent magnet engages with an L-shaped pole piece 3 of magnetic material which is secured to the framework by screws 4, also of magnetic material, which also clamp to the front of the frame I a plurality of laminations 5 forming amagnetic core carrying the bobbin 6. The laminations 5 have a magnetic gap 1 within which is located the lower end of the armature 8 which is mounted for rocking movement about a fiat spring 9, cpposite ends of which are clamped in a bracket member If! secured to the front of the frame I. The armature is made of two plates 8, 8" between which the spring 9 is clamped, pole shoes ll being formed at the upper ends of these plates so as to lie opposite a pole piece 12 in contact with the upper end of the magnet 2. This pole piece I2 is. adjustable towards and away from the pole shoes H by means of the screws 13 movable in slots (not shown) in the frame member I, whereby the gap between the pole shoes I I and the pole piece I: may be adjusted.

The upper end of the armature carries movable contacts I4 adapted to co-operate. with fixed contacts l5 carried by the framework, as more fully hereinafter described. The bobbin 6 may carry one or more windings according to requirements, the various contacts and windings being connected to insulated contact pins l 6 projecting through a base member 11, the whole relay being enclosed by a cover 18.

The movable, contacts 14 are carried by'a leaf spring is secured between the two plates 8, 8 constituting the armature and projecting from the upper end thereof. The free end of the leaf spring I9 is enlarged in area, as shown at 20, and provided with an aperture 2| within which is moulded a member or block 22 of insulating material, through the centre of which passes a metal member so as to project from opposite sides thereof to form the contacts [4 and be insulated from the leaf spring. To each side of the upper end of the armature is also secured a leaf spring 23 of thinner material than the main leaf spring E9, the free ends. of each of the springs 23 bearing on opposite sides of the insulating member 22 and as close as possible to the associated contact M, the moulded insulating member being formed with a small ridge 24 on each side, each of which lies between the free end of the leaf spring 23 bearing on that side and the adjacent contact I4. Electrical connection with the movable contacts is effected by fiexible leads 40.

The relay shown is a double-pole relay and carries two sets of contacts l4 and associated leaf. springs l9 and 23 from the top of the armature, the movable contacts 14 being adapted to engage with two sets of fixed contacts E5 on each side thereof. It will be understood, however, that the relay may be constructed with only a single movable contact assembly with a fixed contact on each side thereof, or alternatively with more than two movable contact assemblies and a corresponding number of fixed contacts.

In the case of a multi-pole relay, it is important that the armature contacts should make simultaneously with all the fixed contacts on one side of the armature. A feature of the invention therefore consists in making the fixed contacts independently adjustable towards and away from the armaturecontacts. I I t In the embodiment shown in Figs. 1 to 5, each of the fixed contacts is carried by a strong leaf spring 25 which is secured at one end by a screw 26 to a U-shaped metal member 21 of which the limbs slide in grooves or channels 28 at opposite faces of an insulating block 29 car ried by the frame l. The other end of the spring 25 frictionally engages the surface of the metal member 21. A threaded pin 30 projects from opposite sides of the insulating member and spaced from the movable contacts carried thereby.

4. Device as claimed in claim 3, wherein the surface of the insulating member between a movable contact and the free end of an outer the member 2! between thelimbsthereof and passes through an aperture 3! in theinsulating block 29. A pair of helical springs 32 are fitted in apertures 33 in the block 29 and tend to move the member 21 and the contact If) carried thereby towards the armature. The springs 32 are held'compressed and the position of the fixed contact is adjusted by a nut 34 on the end of the threaded pin 39, the nut 34 bearing against the outer surface of the insulating block 29.

Figs. 6 and 7 show a modified arrangement for adjusting. the fixed contacts. In this embodiment the contacts l2 are carried bystrong leaf springs 35 from metal blocks 36 supported in an insulating manner from the frame I. Through each of these blocks passes an adjusting screw 37, the inner end of which bears on the end of the leaf spring 35 to move it and the contact I5 carried thereby towardsor away from the armature contact. The block 36 is formed with a slot 33 across which the screw 3] passes, tightening the screw 39 to close the gap causing the screw 31 to be locked inthe adjusted position.

With this method of adjustin the fixed con tacts, the friction at the free end of the leaf spring 35 varies with the adjusted position of the contact, instead of remaining constant as with the embodiment shown in Figs. 1 to 5. This presents advantages for high speed operation.

Whilst particular embodiments have been described, it will beunderstood that various modications may be made without departing fromthe scope of .the invention as defined by the appended claims.

I claim:

1. In a polarisedflrelay having a balanced armature from which the movable contacts are supported, a balanced armature assembly comprising an armature, a central leaf spring extending from said armature, an insulating member mounted adjacent the free end of said central leaf spring, electric contacts carried by said insulating member, and two outer damping leaf springs disposed respectively on each side of said central leaf spring, said outer springs being each secured at one of their ends to the armature and having their free ends pressing respectively on opposite sides of the insulating memher and spaced from the contacts carried thereby.

2. Device as claimed in claim 1, wherein the surface of the insulating material between a movable contact and the free end of an outer leaf spring is formed with a ridge.

3. In a polarised relay having a balanced armature from which the movable contacts are supported, a balanced armature assembly comprising an armature, a central leaf spring projecting from said armature, an aperture in said central spring, a member of insulating material leaf spring is formed with a ridge.

:5. In a polarised relay having a balanced armature from which the movable contacts are supported, a balanced armature assembly comprising an armature, at least two central leaf springs projecting from said armature and with their surfaces lying in the same plane, each of which carries an insulating member carried at thefree end of each of said central leaf springs, movable contacts carried by said insulating membersand projecting from opposite surfaces thereof, a plurality of pairs of outer leaf springs each pair being associated with one of the central leaf springs, the springs of each pair being disposed respectively one on each side of the asso ciated central leaf spring, said outer springs being secured at one of their ends to the armature and having their free ends pressing respectively on opposite sides of the insulating member of the associated central leaf spring and spaced from the movable contacts carried thereby.

6. .Device as claimedin claim 5, wherein each central leaf spring is formed with an aperture within which the insulating member is secured, a conducting member passing through the insulating member and projecting from opposite sides thereof to form the movable contacts.

T17. Device as claimed in claim 6, wherein the surfaces of the insulating members are formed withridges positioned between the movable contacts and the free ends of the adjacent outer leafsprings.

8. In a polarised relay having a balanced armature from which the movable contacts are supported, a balanced armature assembly comprising an armature, a central leaf spring projecting from said armature, at least one slot in said leaf spring dividing said central leaf spring into at least two limbs each of which carries an insulating member at its free end, movable contacts carried by said insulating members and projecting from opposite surfaces thereof, a plurality of pairs of outer leaf springs each pair being associated with one of the limbs, the springs of each pair being disposed respectively one on each side of the associated limb, said outer springs being secured at one of their ends to the armature and having their free ends pressing respectively on opposite sides of the insulating member of the associated limb and spaced from the movable contacts carried thereby.

'9. Device as claimed in claim 8, wherein each limb is formed with an aperture within which the insulating member is secured, a conducting member passing through the insulating member and projecting from opposite sides thereof to form the movable contacts.

10. Device as claimed in claim 9, wherein the surfaces of the insulating members are formed with ridges positioned between the movable con- 5 tacts and the free ends of the adjacent outer leaf springs.

11. In a polarised relay having a balanced armature from which the movable contacts are supported, a balanced armature assembly comprising an armature, a central leaf spring extending from said armature, an insulating member mounted adjacent the free end of said central leaf spring, electric contacts carried by said insulating member, and two outer damping leaf springs disposed respectively on each side of said central leaf spring, said outer springs being made of thinner materia1 than the central leaf spring and being secured at one of their ends to the armature and having their free ends pressing respectively on opposite sides of the insulating 6 member and spaced from the contacts carried thereby.

RAYMOND JOHN JOSEPH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

